Raffle
$50 a spot would probably be wise as many fans would want to buy a single ticket, but wouldn't be able to spend $100 as comfortably. I think the 30 day stipulation would help accelerate the buying as well. When it's more than half sold people wouldn't want to miss it, just human nature.
If there is an auction I reccomend setting up a Paypal account for ease of payment and tracking paid entries. Also be precise in the setup of the auction rules and stick to them so nobody calls foul.
I'm down for 6 of 200 tickets ($300), plus the others who've posted looks like nearly 10% are "sold".
Good luck with this sale no matter what you decide to do. The selling point here is that our buying a spot helps keep this great player in the game as well. Also great promotion for a noted cuemaker.